Foreign Relations of the United States, 1958–1960, National Security Policy; Arms Control and Disarmament, Volume III

240. Memorandum of Conversation⁰

Washington, January 19, 1960.

SUBJECT

• Threshold Proposal for Nuclear Test Negotiations

PARTICIPANTS

• State
  • Under Secretary Merchant
  • S/AE—Mr. Farley
  • S/AE—Mr. Sullivan
  • S/AE—Mr. Baker
  • S/AE—Mr. Gotzlinger
• CIA
  • Mr. Allen Dulles
  • Dr. Scoville
  • Col. Smith
• AEC
  • Mr. McCone
  • Dr. English
  • Gen. Starbird
• DOD
  • Mr. Knight
  • Gen. Loper
  • Gen. Fox
• White House
  • Dr. Kistiakowsky
  • Mr. Gray
  • Mr. Keeny

Mr. Merchant referred to the draft instruction (Tab B)¹ authorizing the US delegation to propose an approach based upon a signal strength threshold for underground tests. He said that Secretary Herter considers it politically and tactically advisable to make this proposal now. It will demonstrate that the US is prepared to agree to a cessation of underground tests, to the extent that adequate safeguards can be applied. The Secretary foresees some difficulty with the British in regard to a moratorium on cessation of all underground tests. Therefore we do not discuss this matter with the UK until the Secretary sends a reply to Selwyn Lloyd’s letter of January 14.² Mr. Merchant then read the agenda (Tab A) for the meeting and invited discussion of the first question, namely, whether we should advance a threshold proposal in the Geneva negotiations at this time.

Mr. McCone commented that he is agreeable to the idea of a threshold proposal. This approach is consistent with our thinking since the beginning of negotiations. The late Secretary Dulles foresaw its presentation but was reluctant to put it forward until differences on the on-site inspection question actually developed in the conference. Mr. Quarles had likewise supported this approach. There are of course some difficulties. As a preface to any detailed discussion about the threshold, the US must make clear that it insists on controls for any environment where tests are to cease. The first paragraph might be improved by referring to Khrushchev’s January 14 speech before the Supreme Soviet in which he admits that certain types of underground tests might go undetected. Khrushchev thus admits that in some areas there can be no guarantee of compliance, that the treaty must operate partly on faith.

Mr. Merchant said the second paragraph of the draft instruction under consideration (Tab B) makes clear that there will be cessation in only those environments where adequate controls are now available.

General Starbird stated he could find nothing about an atmospheric ban in the instruction. Should we include some instructions conditioned on the Soviet reply to our general approach? Mr. Farley explained that the intent of this paper is a modification from a comprehensive approach to a limited approach. This proposal is an intermediate step on the way to re-introduction of the atmospheric proposal and is thought to be more advantageous than an immediate proposal to ban atmospheric tests. It is doubtful, however; whether we can, in this same instruction, postulate any specific course of action on the basis of various Soviet responses.

Mr. Knight reiterated that Department of Defense technical people still have reservations on the practicability of the threshold idea, whether it can be adequately controlled. DOD technical people would require three more years to prove it workable; however, DOD will abide by the decision of the group. Mr. McCone commented that the late Under Secretary Quarles had called the threshold idea a logical approach. Perhaps it was not so much a question of logic as one of reluctance to enter into a very complex negotiation. General Loper advanced a nonmilitary consideration, the Soviet reply to this proposal. He thought they would say the threshold plan will enable the US to go on testing and yet spy on the USSR at the same time. Mr. Merchant agreed, and said he was under no illusion that the Soviets would accept this proposal. However, we must balance this against the gain in the US posture; we would show our willingness to accept a controlled ban on underground tests. Secretary Herter believes this is good political tactics, a desirable intermediate step.

Dr. Kistiakowsky was unable to understand the concern of the Department of Defense technicians. Seismologists have long understood the measurement of magnitudes. This is elementary; the margin of error is only Q–1 magnitude units. To distinguish between an earthquake and a nuclear explosion is much more difficult. It will require years of research to perfect the techniques. He feels, however, that under the present proposal this particular distinction need not be made. It is the discovery of events and their measurements that is important. Then the percentage would be applied.

General Loper thought an error factor of 2 has been used in arriving at an estimated total number of events. He then referred to Supnu 825³ in which the UK delegate also emphasizes the importance of agreed criteria. According to the UK statement, if there is no agreement on criteria from the first, there is no guarantee that a single inspection will take place. Dr. Kistiakowsky said that magnitude will be the key criterion. The uncertainty in our estimate as to the number of events which would occur was an argument against use of a numerical quota, but not an argument against use of a percentage quota.

Mr. McCone noted that, in the course of his speech before the Supreme Soviet Khrushchev criticized Western moves to exclude underground tests; he implied they are simply designed to justify the resumption of testing.⁴ Therefore, to accept the proposal now under discussion, he would have to reverse himself. Is he likely to do so? Perhaps a different approach would be advisable. Mr. Khrushchev has merely said he would not test in the Soviet Union provided the western powers do not resume testing. Perhaps we should go further and say we would not ever test in the atmosphere and attach no conditions. He asked whether the threshold proposal had been re-examined in light of the Khrushchev speech. Mr. Merchant felt that Khrushchev’s pronouncements should not cause us to forego a proposal which we believe beneficial. The Russians have reversed themselves before. Mr. Allen Dulles noted that Khrushchev has left himself a way out of an agreement to ban atmospheric tests in case the French start testing. Mr. Farley suggested that we must assess the proposal in the light of whether it would be useful even if it were turned down. Even if there were only a 1% or 5% chance of acceptance such a proposal might improve our public position.

Mr. Merchant thought we should save any proposals as to unilateral renunciation of atmospheric tests until after this proposal is turned down. Mr. Farley believed that the public reaction to the proposal would be favorable in any event. If the Soviets turn it down, world opinion will be likely to consider it in terms of a U.S. proposal and a Russian “no”. The onus for the refusal will be on the Russians. Mr. Merchant felt that a posture of willingness to cease all tests that it is technically feasible to control, and of earnest desire to lower the threshold as detection capabilities improve, places us in a particularly good position in the eyes of the public; it will accept the US presentation. Mr. Farley recalled that even a person as critical of our efforts as Senator Humphrey has urged presentation of a threshold proposal calling for a threshold of 5 KT.

Mr. Merchant said that we need to reach a decision in principle to move ahead. If we cannot reach agreement here we should go to the President for a decision. He believed too, in the light of Mr. McCone’s emphasis on the need for stressing the principle of ceasing tests only in environments subject to control, we should make that provision in the instruction a separate paragraph and spell it out a little. Mr. Knight reiterated that DOD will leave to the consensus of the meeting the decision whether a threshold proposal should be advanced. Mr. Dulles suggested working the Khrushchev speech into the draft instruction, especially the part about the necessity for “good faith” in place of adequate safeguards. The people of the United States know all about Soviet “good faith”. That’s why they will approve the threshold proposal, which makes provision for the necessary controls. Mr. McCone and Mr. Farley suggested effective use could be made of Khrushchev’s letter to the President on April 23 in which he said we could guarantee strict observance of the treaty. Mr. Gray said he had no ideas to present at the moment. It seemed to him that the Department of State and Dr. Kistiakowsky favor the threshold proposal strongly, AEC is willing to go along, and DOD is a little reluctant but also willing to go along. Mr. Merchant summarized what he believed to be the unanimous view of the group. First of all, as provided in the first sentence of the proposal, we should consult with the U.K. Second, we should prepare a separate paragraph strengthening the idea expressed in Mr. McCone’s memo submitted to the January 12 meeting of principals.⁵ We should also weave the Khrushchev speech into the proposals. After that, we should clear the proposal with the principals. We should plan another meeting only if a dividing issue arises. Mr. Gray asked whether the threshold proposal might be inconsistent with anything the President may have said or written to Khrushchev or Macmillan. Mr. Farley said he know of no such inconsistency. The threshold proposal is an intermediate step between the President’s proposals of April 13 and May 5. Mr. Merchant recalled another agreed point: General Loper’s point that an inspection request cannot be subject to a veto.

Dr. Kistiakowsky said he had some misgivings, because the threshold proposal is, of course, more complicated by far to negotiate than a comprehensive ban or a ban on atmospheric tests. To reduce any unfavorable political effect, it is advisable to emphasize the phased aspect of this proposal. The recommendations of the panel had been very conservative. Seismologists agree that a lot of progress can be made on the problem of identifying a disturbance, whether it is an earthquake or a nuclear detonation. So, this is just a phased approach toward a more comprehensive ban which will become technically feasible after more study. Now, that a substantial amount of money has been released for research in this field some progress could be expected. Mr. Dulles recalled that Khrushchev himself always talks of disarmament by stages.

Mr. McCone suggested an improvement in paragraph 3 on page 3. Instead of the words “US feels obligated to proceed …” in the last sentence, we should reverse the emphasis and state, “the U.S. will proceed to develop an improved detection system.” The idea of a joint program should then be mentioned. Mr. Dulles suggested that in the first paragraph the words “adequate safeguards can be applied” might be changed to “effective controls can be applied.” Dr. Kistiakowsky questioned whether the words “all events located by the system,” last sentence, paragraph 4, does not provide excessive coverage. We should add the idea that only events “above the threshold” would be inspected.

Mr. Knight referring to the second agenda item, initiated a discussion on the magnitude of the threshold by proposing a level of 5. He quoted former Secretary of the Air Force Douglas as having been in favor of this figure. He stated it would be of advantage to set our initial proposal at a figure somewhat higher than the lowest magnitude we could ultimately accept. A magnitude of 5 makes the area in which inspection is required more nearly commensurate with the number of inspections that seem feasible. However, the Department of Defense will in this case too abide by the consensus of opinion at this meeting.

Mr. Farley stated that magnitude 4.75 is just about the maximum size underground test that has ever been conducted. The idea of consolidating existing knowledge and experience is perhaps better served by this threshold, equivalent to 19 kilotons, than by one established at the 43 kiloton level. Mr. Merchant said that State Department holds no particular brief for a 4.75 level. State Department will be guided by DOD and AEC on this matter. The arguments against the 5 level seem to be this: The larger the permissible test, the less effort, it appears, the US has made to cut down on underground testing. Also, it should be recalled, the Soviets argue that a signal magnitude of 4.75 corresponds to only a 1.97 kiloton device. They are hooked with this low estimate. The arguments for a 5 level, on the other hand, include the fact that it’s a nice round figure and it is easier to negotiate with a round figure. Mr. Gray expressed opposition to a negotiation about a threshold magnitude number. We should stand on our proposed number. Mr. McCone said the AEC approves a magnitude of 4.75. If the threshold is set at a lower figure, the temptation to decouple increases. Dr. Kistiakowsky called 4.75 an average reasonable figure. He believed a figure of 5 to be hard to justify politically; also it will not provide as many inspections as we want. If the threshold is less than 4.75, more inspections will be required to create an effective deterrent. Mr. Merchant said that 4.75 appeared to be acceptable to the group. General Loper recalled that 4.75 had been discussed with the British, and they seem to like this figure best. DOD believes this figure is acceptable provided that agreement can be reached on a reasonable number of inspections. The level of inspection must bear an appropriate relationship to the number of located events or unidentified events. We must insist on a quota which is a satisfactory percentage of events. The percentages Used in paragraph 6 are too low; we have to try to negotiate for a higher percentage.

Mr. Knight advanced 50% as a realistic proposal, in place of 10%. General Loper pointed to the magnitude tables (Attachment to Memorandum of Conversation, January 8, 1960)⁶ which show the average annual number of all located events in the USSR to be 105. That would give us only 10 inspections, on the basis of the proposed percentages. Perhaps there will only be half the average number of events in one year and, therefore, only five inspections. That would be too low to serve as a deterrent. Mr. McCone suggested that 30% of all events above 4.75 magnitude unidentified by US criteria or, alternatively, 20% of all events above 4.75 magnitude located by the system should be subject to inspection. That will provide an annual average of 21 inspections, by either method. Dr. Kistiakowsky stated that the percentages proposed in the instruction supply an effective deterrent. It’s always possible that a single explosion might go unobserved, but not a series. However, if these percentages may become subject for negotiation, Mr. McCone’s suggested percentages should be used. This is a matter of conference tactics. Mr. Merchant suggested substituting 30% and 20%, as suggested by Mr. McCone. Mr. Farley stressed the importance of a proposal which is not prejudical in the UK view. Mr. McCone replied that Prime Minister Macmillan had once suggested one inspection every two weeks as an effective deterrent. Thus 21 inspections a year might be suitable for him. Mr. Merchant said it appeared 30% and 20% is the proposal acceptable to the group.

General Starbird said that the decision to advance paragraph 6 in the form of a proposal makes it necessary to give Ambassador Wadsworth some type of instruction as to what to answer when he is asked what we intend to do about a moratorium and about high altitude testing. He suggested that paragraph 7 should be re-worded so that Ambassador Wadsworth would be authorized to explain what our position will be to the Soviets as well as to the UK. General Loper concurred but considered the final two sentences of paragraph 7b too specific for decision now. We might, for example, in connection with high altitude treaty language want to apply the threshold idea. It was agreed these two sentences should be deleted.

Mr. McCone concluded with a recommendation that we remind the UK of a few matters. First, Mr. Macmillan had himself told Mr. McCone that he wouldn’t agree to a suspension of tests without absolute safeguards. [2-1/2 lines of source text not declassified]

0. Source: Department of State, Secretary’s Memoranda of Conversation: Lot 64 D 199. Secret. Drafted by Gotzlinger and approved in M on January 29. For Kistiakowsky’s account of this meeting, see A Scientist at the White House, pp. 232–233.
1. Tabs A and B are in the Supplement.
2. In his January 14 letter, Lloyd agreed with the threshold concept at least to the extent that it permitted the negotiations to go beyond an atmospheric treaty, but had serious doubts that the Soviet Union would accept a treaty that did not ban all tests, at least temporarily. The Soviets would charge, according to Lloyd, that the West wanted a costly inspection system for intelligence purposes while still allowing a continuation of weapons development. The result would be a serious propaganda setback for the West. Therefore, Lloyd suggested that in spite of scientific difficulties, it was in the West’s interest to come to an arrangement with the Soviet Union in which all tests would cease, even if the moratorium on underground testing would be temporary. (Eisenhower Library, White House Office Files, Project Clean Up, State Mepco Cables) See the Supplement.
3. Dated January 15. (Department of State, Central Files, 700.5611/1–1560)
4. See Documents on Disarmament, 1960, pp. 4–16, for extracts.
5. See footnote 5, Document 239.
6. The memorandum of conversation and its attachment are in Department of State, Secretary’s Memoranda of Conversation: Lot 64 D 199. See the Supplement.